This invention relates to an apparatus for separating aerosols or particles from a gas stream.
Published European patent application no. EP 685,635 discloses a device for an internal combustion engine with which oil or oil particles are removed from crankcase gases. This so-called crankcase venting has a vent line through which a medium may flow; at least one oil separator is provided in this vent line, and a return line for separating oil leads from this oil separator to the crankcase. The oil separator is an electric filter designed as a tubular electric filter. The electric filter consists of a discharge electrode arranged in the interior of the pipe with a medium flowing through it, an electric d.c. field being generated between the pipe wall and the discharge electrode for charging the oil droplets flowing through. The oil droplets are separated on the inside of the pipe through which they flow, forming an oil film there. This oil film flows in the direction of the oil pan. One disadvantage of this device may be regarded as the fact that the corona electrode is situated in the aerosol stream and thus there is the risk of soiling the electrode. This soiling alters the electrostatic conditions, which in turn alters the deposition effect. It is impossible to clean the electrode because of the built-in conditions.
In addition, published German patent application no. DE 196 42 218 describes an oil separating device, in particular for internal combustion engines of motor vehicles. It consists of an oil separator element arranged in a housing. The oil separator element has a first and a second electrode, each of which is connected to a high voltage source; the two electrodes have different polarities and are mounted in the flow path of the oil and gas mixture. With this arrangement, there is also the risk that the dirt particles might be deposited on the electrodes and thus greatly impair the effect of the separator.